Fluid catalytic cracking (FCC) is a well-known process for converting relatively high boiling point hydrocarbons to lower boiling point hydrocarbons in the heating oil or gasoline range. Such processes are commonly referred to in the art as “upgrading” processes. To conduct FCC processes, FCC units are generally provided that have one or more reaction zones, in which a hydrocarbon stream is contacted with a particulate cracking catalyst. The particulate cracking catalyst is maintained in a fluidized state under conditions that are suitable for converting the relatively high boiling point hydrocarbons to lower boiling point hydrocarbons.
While hydrocarbon streams such as vacuum gas oil, reduced crude, or other petroleum-based sources of hydrocarbons have commonly been upgraded through FCC processes, there is a general desire to upgrade biofuels along with the hydrocarbon streams in the FCC processes. By upgrading biofuel along with the hydrocarbon streams, the resulting upgraded fuel includes a renewable content and enables net petroleum-based hydrocarbon content of the upgraded fuel to be decreased.
Biofuels encompass various types of combustible fuels that are derived from organic biomass, and one particular type of biofuel is pyrolysis oil, which is also commonly referred to as biomass-derived pyrolysis oil. Pyrolysis oil is produced through pyrolysis, including through recently-developed fast pyrolysis processes. Fast pyrolysis is a process during which organic biomass, such as wood waste, agricultural waste, etc., is rapidly heated to about 450 to about 600° C. (about 842 to about 1112° F.) in the absence of air using a pyrolysis unit. Under these conditions, a pyrolysis vapor stream including organic vapors, water vapor, and pyrolysis gases is produced, along with char (which includes ash and combustible hydrocarbon solids). A portion of the pyrolysis vapor stream is condensed in a condensing system to produce a pyrolysis oil stream. Pyrolysis oil is a complex, highly oxygenated organic liquid that typically contains between about 20 to 30% by weight water with high acidity (TAN>150).
Various examples of processing the pyrolysis effluent and a hydrocarbon stream in a catalytic cracking zone are shown in U.S. Pat. Pub. Nos. 2014/0034550 and 2014/0034552. In as much as these processes require increased temperatures, the processes require a net input of energy.
Accordingly, it would be beneficial to have one or more processes in which the amount of energy needed for these processes is lower. It would further be desirable if such processes lowered the greenhouse gas emissions of the processing units.